Implantable medical leads typically have a contact for electrical connection to an active implantable medical device and an electrode coupled to the contact via a conductor. The conductor carries electrical signals from the device to the electrode or from the electrode to the device. Leads and conductors are typically insulated such that only the electrodes are in electrical contact with a patient's body when implanted.
Patients in which medical leads are implanted may, on occasion, undergo magnetic resonance imaging (MRI) procedures to diagnose a condition, which may or may not be related to a condition for which the implanted lead is intended to treat or monitor. Regardless of the reason for the MRI procedure, MRI can result in heating of the conductor induced by the radio frequency (RF) field in MRI. Because the conductor and lead body is typically insulated, the heat tends to concentrate at the exposed electrode. Such heating of the electrode can be undesirable if the temperature rise is large or sustained.
A number of solutions have been developed to produce MRI-safe leads. However, additional developments in the production of MRI-safe leads would be desirable.